A dispute between Major League Baseball and its umpires over background checks turned ugly Wednesday, when a spokesman for the umpires union charged MLB's security investigators with acting like "secret police" in their efforts to dig into the personal histories of umpires.

Lamell McMorris, a spokesman for the World Umpires Association, told ESPN.com that baseball investigators have gone into neighborhood homes in recent weeks and asked a series of provocative and potentially defamatory questions about umpires.

According to the WUA, neighbors of Greg Gibson and Sam Holbrook -- MLB umpires who live in Northern Kentucky -- were asked if the two men are members of the Ku Klux Klan.

"Major League Baseball's security staff is essentially defaming umpires in their communities by conducting, strange, surreptitious and poorly-executed investigations resembling that of secret police in some despotic nation," McMorris said.

"The claims of inappropriate questioning by individuals conducting background checks was brought to our attention and looked into thoroughly," Solomon said. "After investigation, it was determined that these claims were inaccurate. Questioning was conducted with a written script consistent with common practice and there was no inappropriate conduct on behalf of the investigators."

Veteran umpire John Hirschbeck, president of the World Umpires Association, said he's not opposed to background checks. But Hirschbeck said Major League Baseball investigators "crossed the line" by fostering false or negative impressions about umpires among their friends and neighbors.

"We know we live in a fishbowl, and it's different than other people," Hirschbeck said. "We're not against background checks. But this should have been done uniformly and in a more respectful way, so that things like this don't happen."

Baseball attempted to institute more extensive background checks in August in response to the gambling scandal involving NBA referee Tim Donaghy.

The World Umpires Association refused to sign off on the initiative, insisting that the matter be resolved through collective bargaining. But MLB has maintained that umpire background checks are necessary to ensure the game's integrity, and said it is legally within its rights to conduct the checks.

While the umpires' 78-page labor agreement
makes no specific mention of background checks, it does include a passage about off-field conduct.

"Off the field, umpires shall conduct themselves in a manner consistent with an exemplary image and reputation of Major League umpires," the section reads.

Umpire and referee conduct has become a hot-button issue in all sports since the news broke that Donaghy, a 13-year NBA referee, was under investigation by the FBI for allegedly betting on games and providing inside information to gambling associates.

Donaghy, 40, resigned in July and pleaded guilty in August to conspiracy to commit wire fraud and transmitting betting information across state lines. He is scheduled to be sentenced April 18 on two felony charges.

McMorris said that MLB investigators have been "misrepresenting" themselves as friends or acquaintances of umpires in the course of conducting background checks. He said the World Umpires Association spoke with neighbors of Gibson and Holbrook in Northern Kentucky, and they relayed some of the questions they were asked by MLB security officials.

Among other things, McMorris said, the neighbors were asked if the umpires grow marijuana, throw wild parties, engage in spousal abuse or live beyond their means financially. But the WUA reserved its harshest criticism for the question about the Ku Klux Klan.

"We're in an environment where there have been incidents with nooses in the country," McMorris said. "There was the 'Tiger issue' in a golf magazine, and we're in the middle of a presidential election where clearly race is a major factor. And now you're going to knock on a neighbor's door and ask if an umpire is a member of the Ku Klux Klan?

"That shows a tremendous amount of ignorance and insensitivity, frankly. And we take exception to it."

According to The Associated Press, Hirschbeck and McMorris said Tom
Christopher, the Milwaukee-based supervisor of security and
investigations in the commissioner's office, had asked questions
about Klan membership to neighbors of umpires Gibson and
Holbrook. In addition, Hirschbeck said
similar questions had been asked to neighbors of umpire Ron Kulpa, who lives in suburban St. Louis.

Alison Rohan, who lives across the street from Kulpa in Maryland
Heights, Mo., told The Associated Press that Christopher knocked on her door two or three
weeks ago and gave her his card.

"He explained they were going to be talking to neighbors and friends because of the problems with the basketball league and that
Ron knew about it," she said. "He listed about 10 different
questions, the first one being did Ron live out of his means? For
example, does he drive a Rolls-Royce?''

Rohan told AP she told Christopher that Kulpa lived in a manner
similar to that of his neighbors.

"He asked if Ron belonged to any groups or organizations," she
said.

"Groups?" she remembered replying.

"You know, like the KKK," she said Christopher told her.

"We both laughed and I said no," Rohan said. "He belongs to a
neighborhood Harley-riding group of dads."